Commonly-owned U.S. Patent Application Publication No. 2017/0096828 of Moore, et al., details filtration aspects of certain APCs. Cleaners described in the Moore application may be hydraulic, pressure-side APCs, in that they may communicate with outlets (“pressure sides”) of, typically, remotely located water-circulation pumps. These cleaners also may include canisters as debris filters, with the canisters being “designed so as not to be wholly internal to” bodies of the APCs “yet not materially increase hydraulic drag as” the APCs move autonomously within swimming pools. See Moore, p. 1, ¶0018.
U.S. Patent Application Publication No. 2015/0337555 of Hui, et al., discloses a manually-operated (and thus not automatic) pool cleaner having a handle to allow a person to move the cleaner within a pool. The manual cleaner may include both a “mesh filter” for removing larger pieces of debris and a “filter bag” for removing finer pieces of debris. As described in the Hui application, pool water flows through the mesh filter and then through the filter bag to remove, consecutively, larger and finer debris. See Hui, p. 7, ¶0101.
Neither the Moore application nor the Hui application addresses by-passing part of a dual-stage filtration system. Neither application discusses a possibility of having a permanent by-pass, in which a portion of the pool water entering the cleaner always by-passes the small-debris filter, and neither contemplates making a small-debris filtration stage optional while retaining a large-debris filtration stage. These and other issues remain to be resolved in connection with APCs.